1. Field of the Invention
The present invention relates generally to medical implants. Particularly, the present invention relates to fracture plates and cages. More particularly, the present invention relates to a bone loss plate for the rigid fixation of long bone fracture where there is significant bone loss at the fracture site or bone loss gaps caused by pathological processes.
2. Description of the Prior Art
Fracture plates and cages have been in use for years. Typically, fracture plates and cages are comprised of separate fracture plates and metallic mesh cages. Plates are used to immobilize bone fractures and to maintain alignment during the healing process. Cages have been used to make up the space in areas of bone loss due to fracture or other pathologic processes.
The main problem with conventional fracture plates is that plates cannot close gaps between the fractured ends of severely damaged bones. Bone does not heal if significant gaps exist between fracture fragments of broken or otherwise damaged opposing bone ends. If there is bone loss at the fracture site the use of a conventional plating system requires the fracture ends to be pulled together shortening the overall length of the original bone.
Alternatively, mesh cylindrical cages filled with osteogenic material may be inserted into the gap prior to assembling the plate system to the fractured bone. A drawback of conventional cages used to fill gaps in damaged bone is that the cages may migrate out of position. Additionally, conventional cages do not provide immobilization of the fractured bone nor can they maintain alignment of the fractured bone.
While these devices may be suitable in some circumstances, they are not as suitable for the rigid fixation of long bone fracture where there is significant bone loss at the fracture site or bone loss gap caused by pathological processes.
U.S. Pat. No. 4,938,768 discloses a bone gap bridging and fusing device. The bone gap bridging device includes first and second pin members adapted to be placed in axial openings formed in the opposed remaining bone portions. Each pin member includes a head and the heads of the pin members interengage one another to prevent relative rotation between the pin members. A collar telescopes over the interengaged heads to lock the pin members axially relative to one another.
This device suffers the disadvantage that tapered openings in axial alignment must be formed in the ends of the bone portions in order to receive the pin members of the device. Additionally, the collar and the pin members must have mating threads as well as set screws to fix the collar in position relative to the pin members, which adds to the cost of the device.
Therefore, what is needed is a device and method to rigidly fix a long bone fracture where there is significant bone loss at the fracture site or caused by pathological processes. What is also needed is a device and method that also fills the gap produced by the bone loss so that shortening does not occur. What is further needed is a device and method that provides immobilization and maintenance of alignment of a bone fracture while eliminating or minimizing the shortening of the bone caused by bone loss.